21663141 has 8 divisors (see below), whose sum is σ = 29816064. Its totient is φ = 13976160.

The previous prime is 21663139. The next prime is 21663149. The reversal of 21663141 is 14136612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21663141 - 2¹ = 21663139 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21663149) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 116376 + ... + 116561.

It is an arithmetic number, because the mean of its divisors is an integer number (3727008).

Almost surely, 2^21663141 is an apocalyptic number.

It is an amenable number.

21663141 is a deficient number, since it is larger than the sum of its proper divisors (8152923).

21663141 is a wasteful number, since it uses less digits than its factorization.

21663141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232971.

The product of its digits is 864, while the sum is 24.

The square root of 21663141 is about 4654.3679484974. The cubic root of 21663141 is about 278.7664313613.

Adding to 21663141 its reverse (14136612), we get a palindrome (35799753).

The spelling of 21663141 in words is "twenty-one million, six hundred sixty-three thousand, one hundred forty-one".